Oscillograph circuit to avoid distortion



June 1949- M. MARON 2,473,718

' OSCILLOGRAPH CIRCUIT TO AVOID DISTORTION Filed Sept. 21, 1946 INVENTOR OR EY Y Patented June 21, 1949 STATES PATENT OFFICE OSCILLOGRAPH CIRCUIT. TO AVOID DISTORTION MeyerMaron, Passaic, N. J.,.assignor to Allen'B. Du Mont Laboratories, Inc.,- Passaic, N. Is, a corporation of Delaware- Application September 21, 1946, SerialNo. 698;487

, 8 Claims.

1 This I invention relates to a polar coordinate cathode-ray. tube oscillograph. Heretofore ob jections have been encountered withoscillogra-phs of .this'sort dueto'the fact that the pattern traced on the face or screen of the tubes was often dis- ,2 potential that is theaverage potential of.v the pairs of deflection plates 1 and'8 by beingcon nected-.170 said plates through resistors. I|-,. i8;:=.l 9 and 20. The cathode of tube Ill and theseco'nd anode ii are maintained at the same potential torted by defocuss'i'ng of the beam or the patsince they are directly connected by lead 2|. The tern. was. subjected to trapezodial distortion. potential of lead It diflers from that of leadll "'With the present invention a circuit is proonly to the extent or the operating grid biasrot vided of such a character that the average potube It. Therefore the potential of -leads2-I and tential of the four deflection plates of an oscillosecond anode S is kept very close to that ofwthe graph: is-maintained at the potential of the secpairs'of deflection plates Land-'8. ond anodeof the cathode-ray tube. It will be obvious that when the averagezpo The-invention may be understood from the tential' of the two pairs ofeplates 'l and-asis-prm descriptionzin connection-with the accompanyvided by thesame signal, orwhen-thesamesignal ina drawing: which is a diagram showing a cathis modulating both pairs-ofplatessimilarly, the ode-ray tube and connections thereto. resistances II2Il need to be connected to only In the drawing, reference character I indicates one pair of plates, since the average potential a cathode-ray tube that is provided with a heater of the other pair of plates is then the same as 2, cathode 3, control grid 4, first anode 5, secthat of the first pair. 0nd anode 6, a pair of horizontal deflection plates What is claimed is: I, and a pair of vertical deflection plates 8. 1. An oscillograph comprising a cathode-ray A triode It has its plate connected to a source tube, having pairs of deflection plates and a first B of positive potential. The cathode H of this and a second anode, and means comprising a triode is connected to one end of a series of revacuum tube and a resistor between each one of sistance l2, I3, I4 and I5, the other end of this said plates and the grid of said vacuum tube to series of resistances being connected to a large maintain said second anode substantially at the negative potential. average potential of said plates, said means in- A lead I6 extends from the control grid of cluding a connection between the cathode of said tube II] to ends of resistances I1, I8, I9 and 20. vacuum tube and said second anode. The other ends of resistances I1 and I8 are con- 2. An oscillograph comprising a cathode-ray nected to opposite plates I of the oscillograph I tube having pairs of deflection plates and a first and the resistances I9 and 20 are connected to and a second anode, and means comprising a opposite plates 8 respectively. The resistance vacuum tube and a resistor between each one of I I to 20 are each large enough to reduce the said plates and the grid of said vacuum tube to coupling of the plates 1 and 8 to a negligible 5 maintain said second anode substantially at the amount. A lead 2| extends from the cathode of average potential of said plates, said means comtube II] to the second anode 6. A lead 22 extends prising a vacuum tube to the control grid of from a sliding contact on potentiometer I3 to the which said plates are connected and to the oathfirst anode 5 for focussing the cathode-ray beam ode of which said second anode is connected. of tube I. Lead 23 extends from a sliding con- 3. An oscillograph comprising a cathode-ray tact on potentiometer I5 to the control grid 4 tube having pairs of deflection plates and a first for intensity control and lead 24 extends from a and a second anode, and means comprising a point between resistances I4 and I5 to the cathvacuum tube and a resistor between each one of ode 3. said plates and the grid of said vacuum tube to Leads, 3|, 32, 33 and 34 are connected to the maintain said second anode substantially at the pairs of deflection plates 1 and 8 in the usual average potential of said plates, said means comway when the device is to be used to cause the prising a vacuum tube to the control grid of beam to trace a pattern on the luminescent face which said plates are connected through high re- 01- the tube. These leads 3| through 34 are consistances and to the cathode of which said secnected to the usual and well known beam de- 0nd anode is connected. flection and positioning circuits identified in 4. An oscillograph comprising a cathode-ray block diagram form by the numerals 35 and 36 tube having pairs of deflection plates and an in the drawing, to provide beam deflecting and anode, and means comprising a vacuum tube centering potentials for the cathode ray tube. and a resistor between each one of said plates The lead It and grid of tube III are kept at a and the grid of said vacuum tube to maintain said second anode substantially at the average potential of said plates, said means comprising a vacuum tube to the control grid of which said plates are connected through high resistances sumcient to prevent objectionable coupling between said plates and to the cathode of which said second anode is connected.

5. An oscillograph comprising a cathoderay tube having pairs of deflection plates and an anode, and means comprising a vacuum tube and a resistor between each one of said plates and the grid of said vacuum tube to maintain said second anode substantially at the average potential of said plates, said means comprising a vacuum tube to the control grid of which said plates are connected, said vacuum tube having a high resistance in its cathode circuit and to the cathode of which said second anode is connected.

6. An oscillograph comprising a cathode-ray tube having pairs of deflection plates and an anode, and means comprising a vacuum tube and a resistor between each one of said plates and the grid of said vacuum tube to maintain said second anode substantially at the average potential of said plates, said means comprising a vacuum tube to the control grid of which said plates are connected, said vacuum tube having a high resistance in its cathode circuit, said vacuum tube having its cathode connected to said anode.

7. An oscillograph comprising a cathode-ray tube having pairs of deflection plates and a first anode and a second anode, and means comprising a vacuum tube and a resistor between each one of said plates and the grid of said vacuum tube to maintain said second anode substantially at the average potential of said plates, said means comprising a vacuum tube to the control grid of which said plates are connected, said vacuum tube having a high resistance in its cathode circuit, said second anode being connected to the cathode of said vacuum tube and said first anode in said cathode-ray tube connected to said high resistance.

8. An oscillograph comprising a cathode-ray tube having pairs of deflection plates and a first anode and a second anode, and means comprising a vacuum tube and a resistor between each one of said plates and the grid of said vacuum tube to maintain said second anode substantially at the average potential of said plates, said means comprising a vacuum tube to the control grid of which said plates are connected, said vacuum tube having a high resistance in its cathode circuit, said second anode being connected to the cathode of said vacuum tube and said first anode in said cathode-ray tube adjustably connected to said high resistance.

MEYER MARON.

REFERENCES CITED The following referemces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,153,638 Norman Apr. 11, 1939 2,180,365 Norton Nov. 21, 1939 2,350,069 Schrader et a1 May 30, 1944 2,391,862 Boyle Jan. 1, 1946 

